<!DOCTYPE html>
<html lang="zh-CN">
	<head>
		<meta charset="UTF-8" />
		<meta name="author" content="wangbo" />
		<meta http-equiv="X-UA-Compatible" content="IE=edge" />
		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
		<title>三角形练习</title>
		<style>
			div {
				width: 0;
				height: 0;
				border: 100px solid red;
        border-top-color: greenyellow;
				/* 右边颜色 */
				border-right-color: aqua;
				/* 边框 底部颜色 */
				border-bottom-color: bisque;
			}
			/* 并集选择器 */
      .c1{
        /* 顶部 左右2侧透明 */
        border-bottom-color: greenyellow;
        border-top-color: transparent;
        border-right-color: transparent;
        border-left-color: transparent;
      }
      .c2{
        /* 底部 左右2侧透明 */
        border-bottom-color: transparent;
        border-right-color: transparent;
        border-left-color: transparent;
      }
		</style>
	</head>
	<body>
		<div class="c1"></div>
		<div class="c2"></div>
	</body>
</html>
